Added required eslint.config.mjs for eslint 10

Author: oliverbeumkes-nhs

services/gp2gp-messenger/eslint.config.mjs

@@ -0,0 +1,37 @@
+import { defineConfig } from "eslint/config";
+import prettier from "eslint-plugin-prettier";
+import globals from "globals";
+import path from "node:path";
+import { fileURLToPath } from "node:url";
+import js from "@eslint/js";
+import { FlatCompat } from "@eslint/eslintrc";
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = path.dirname(__filename);
+const compat = new FlatCompat({
+    baseDirectory: __dirname,
+    recommendedConfig: js.configs.recommended,
+    allConfig: js.configs.all
+});
+
+export default defineConfig([{
+    extends: compat.extends("eslint:recommended", "prettier"),
+
+    plugins: {
+        prettier,
+    },
+
+    languageOptions: {
+        globals: {
+            ...globals.node,
+            ...globals.jest,
+        },
+
+        ecmaVersion: 2020,
+        sourceType: "module",
+    },
+
+    rules: {
+        "prettier/prettier": "error",
+    },
+}]);

services/gp2gp-messenger/package-lock.json

@@ -52,10 +52,13 @@
     "@babel/node": "^7.29.0",
     "@babel/plugin-transform-runtime": "^7.29.0",
     "@babel/preset-env": "^7.29.2",
+    "@eslint/eslintrc": "^3.3.5",
+    "@eslint/js": "^10.0.1",
     "eslint": "^10.1.0",
     "eslint-config-prettier": "^10.1.8",
     "eslint-plugin-jest": "^29.15.1",
     "eslint-plugin-prettier": "^5.5.5",
+    "globals": "^17.4.0",
     "jest": "^30.3.0",
     "jest-when": "^4.0.1",
     "nock": "^14.0.11",